code: def _doc():
      return Document()
  
file_path: bokeh/tests/unit/bokeh/io/test_doc.py
imports: from __future__ import annotations
  import pytest
  import weakref
  from bokeh.document import Document
  from bokeh.io.state import curstate
  import bokeh.io.doc
label_desc: Use image node_id 4 for calling a global function with example usage: _doc() and returns: Document